In classical Latin, the pronunciation of Julius Caesar was Iulius Kai-sahr; but at some point this changed. The Julius is not something I am concerned about, because the "Iulius" is preserved in some Romance languages, like Romanian.

The part I am interested in is the "Caesar" part. In all latin-based languages the pronunciation became Sisar or Seezer/Seezar. The Kaiser in Germanic I doubt has much relevance here, as they have a separate linguistic history. It seems to me that this consonant shift probably occurred fairly early, maybe even in the first 5 centuries AD.

Has anyone here done any phonological studies in this area and have a hypothesis or an answer?

I can help you. In the sumerian language Ki-Shar meant a planet Jupiter. What meant this word at Sumerian?
1) Ki=a little, Small
2) Ki= Hot (definition in grammar)
3) Ki (i) =Rost (a verb in an imperative mood in grammar)
4) Ki (i) = Put on (a verb in an imperative mood)
5) Кi (i) = Dressed. (definition in grammar)
I Will notice that the word "clothes"; and "hot" = "warm" inseparably linked concepts. Sumerian called a planet Earth - Ki that meant:" Dressed in clothes", that is wrapped up in the ATMOSPHERE. From planets of solar system the hot, warm atmosphere still is and at Jupiter. Therefore they called Jupiter - Ki-SHAR ="Wrapped up in the atmosphere (in clothes) a sphere". Venus which too has the atmosphere, sumerian always allocated from total number of planets - ENs = "Brothers" and called Venus as Inanna and as Ishtar- till Flood names. Probably because Venus wasn't "brother", and was a "sister"! So: Dur-Sarru-Kin = "Parking of the Gold Sun", "Base of the Gold Sun" from the point of view of Sumerian and Tatar languages. Sarru-Kin=Sharru-Kin = "Sun Gold". The word KAI-SAhR a word Caesar isn't become casual. The second gloss of "i" or "e" in the word KAI-SAhR - primordial a sumerian gloss (Ki-En=kin=ken=kyon=kon!!!) And only inadequate prasemits could to deform so a primary sumerian sound of i or e, having turned into a. So, from the point of view of sumerian and Tatar languages, latin Kai-Sahr = "the Hot Sphere" = Jupiter.
Again it is necessary to mention that prasemits didn't distinguish hissing sounds and replaced SH sound with the sound of S.
Ke(i)-SHAR became at prasemits to KAi-SAhR ((((

Last edited by ki-en-gar from ki-en-gir; December 5th, 2012 at 08:42 AM.

My "Etymological Dictionary of Latin and Other Italic languages" states that the root caesar- in Latin means "having long hair, one who has combed hair" which was *kaikerksaas in PIE.

As Wikipedia states, the palatalization of the plosive /K/ was a marked difference between vulgar and classic Latin and as most of the Romance languages evolved from this common vernacular they all seem to share that property. Vulgar Latin is usually thought to have originated in the period of the Roman Empire as the language of the soldiers, slaves and the Romanized provinces. So the title was already pronounced in the "broken" way among the common people, while retaining the classical spelling in formal writings.

Isn't Ceasar(See-zar) not an anglicized version of the latin Kai-zar...??

I believe it's the pronunciation in Ecclesiastical Latin as opposed to Classical Latin.

I know in Greek, most the vowel shifts, except for the upsilon, occurred fairly early on, around the turn of the first millennium. But I think Latin was a bit later, though I'm not sure how much later...I'm not quite as familiar with the evolution of the Romance Languages.

Classical Latin, after 100 BC, wrote "Caesar", but still the pronunciation was "Kaisar". From there, barbarian peoples outside the Empire took the word.

As early as the 1st century BC, common people began to pronounce both diphthongs AE and AI, as "E". So Kaisar/Kaesar became Kesar. But this process was a slow one, and was not fully completed until 5th century AD.

In this way, common people, speakers of Vulgar Latin, developed and adopted the writing form Cesar, pronounced "Kesar" or further variants, that Romance speakers use today.

In classical Latin, the pronunciation of Julius Caesar was Iulius Kai-sahr; but at some point this changed. The Julius is not something I am concerned about, because the "Iulius" is preserved in some Romance languages, like Romanian.

The part I am interested in is the "Caesar" part. In all latin-based languages the pronunciation became Sisar or Seezer/Seezar. The Kaiser in Germanic I doubt has much relevance here, as they have a separate linguistic history. It seems to me that this consonant shift probably occurred fairly early, maybe even in the first 5 centuries AD.

Has anyone here done any phonological studies in this area and have a hypothesis or an answer?

In Vulgar Latin the initial "c" before "e" and "i" was palatalized Phonology of Vulgar Latin, in Romanian and Italian it became "tch", in other Romance languages it became "s". "Iulius" in Romanian is not inherited from Latin, it is just a modern borrowing, like "Cezar".

So, is it then that the C in Caesar was pronounced as an "S" or "TS" even in his time?

If this were the case, that would explain why Kaiser the title and Caesar the proper name in German have two separate pronunciations. Seeing as how Caesar became an Imperial title, and likely would have had the "Kaisar" pronunciation from the classical Latin.